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Segway Inventor Dean Kamen Thinks His New Stirling Engine Will Get You Off The Grid For Under $10K

For the new issue of Forbes Magazine I wrote an article about David Crane, the visionary CEO of NRG EnergyNRG Energy. When I met Crane for lunch a couple weeks ago, no sooner had we sat down than he began singing the praises of this new contraption he had in his basement. The machine — which can generate 10 kilowatts of continuous power, fed by Crane’s natural gas line — is a new iteration of an old creation, the Stirling engine. This version, called the Beacon 10, was created after a decade of engineering by famed inventor Dean Kamen.

I caught up with Kamen (who is best known for creating the Segway scooter) over the phone last week to ask him about the device. “We’ve turned his basement into an extension of our laboratory,” said Kamen. “It’s certainly not a machine made for the typical home, but he has a gigantic swimming pool and a huge house.”

With the Beacon 10, says Kamen, “you don’t have to feel guilty heating up the pool.” That’s because of the highly efficient nature of the Stirling engine. First conceived in 1816 by Scottish minister Robert Stirling, the device in its simplest form consists of applying an external heat source to a closed cylinder where the cyclical expansion and compression of air inside the cylinder drives the pistons up and down. Unlike your car, where fuel is combusted inside the engine, the Stirling is an external combustion engine; it can work with any external heat source.

The Stirling is quieter than an internal combustion engine, and it’s more efficient because the heat is retained inside the engine by to do more work rather than allowed to escape to the environment.

Kamen’s Beacon 10 Stirling engine. (Courtesy Deka Research)

Though Stirlings are highly efficient, they haven’t caught on because it takes them a while to warm up and they can’t change power output quickly. That makes them unworkable for cars and trucks, but potentially ideal both for power generation and water heating. More than just a backup generator, these machines, depending on the price of natural gas, could also provide round-the-clock power to a home or business. Beats solar panels.

Kamen’s contribution has been in engineering his Stirling with the most high-performance materials. He started off using skilled welders to put together key parts of the engine made out of exotic alloys. More recently he’s figured out how make those pieces with even more precision using 3-D printing. Crane says a key element in Kamen design was the perfection of a little plastic membrane that looks like a condom. The Beacon, which weighs about 1,500 pounds and is the size of a washing machine, also includes a battery system, which can be integrated with other distributed generation systems like solar panels.

So what’s Kamen’s vision for the future of these things? Well the one in Crane’s basement is far too big for the average American home, generating 10 continuous kilowatts, while most of us only draw about 2 kw. “I love bulldozers, but I wouldn’t put one in my garage,” quips Kamen.

Kamen believes that aside from mansion owners, the Beacon 10 is just right for businesses like laundries or restaurants that use a lot of hot water. With commercialization partner NRG Energy, he’s so far deployed roughly 20 of the machines.

Kamen expects to put them into production within 18 months. “Within two years I would expect high-end builders to be installing them.”

But the 10 kw models are just the beginning. It won’t be long before Kamen has a smaller version ready for commercialization. He’s already been running a 2.5 kw Beacon at his New Hampshire home for four years.

Why not offer the smaller version first? “A 2-kilowatt machine would make one-fifth the power, but wouldn’t cost just one-fifth the money,” says Kamen. That’s why he and NRG will be relying on high-tech early adopters, such as Tesla owners, to buy the first run.

As for cost? Kamen thinks that the 10 kw versions can be manufactured and installed for roughly $10,000 or about $1 per watt. That, however, wouldn’t cover development costs, overhead, or profit margin.

It will be up to Crane’s NRG to determine what to charge for these Beacon machines. A big part of NRG’s plan isn’t to sell them at all, but lease them. Leasing equipment to homeowners and businesses is the same model that NRG and solar-installer upstart SolarCitySolarCity have applied to solar panels. The homeowner leases them for 20 years or so, and agrees to pay NRG a fee per kwh that their own roof generates. If the panels make excess juice, then NRG can make money selling it onto the grid.

The idea is to try the same thing with the Beacon machines. Once the adoption rate is high enough, NRG will be able to network dozens of the devices across a region together. Depending on natural gas prices and levels of electricity demand, there could be times when NRG would send a signal to all the Beacon machines in a region to ramp up to full output and send the excess power onto the grid. ”We don’t think we should be just selling a box,” says Kamen. “We think we should be part of a system of the future, powering the evolution of microgrids.”

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why listen to the EPA.. the market is more credible.. the reason this idea is taking off is because people want it.. demand will outperform the EPA and all the efforts the oil companies put in to squash it.

The idea isn’t exactly new. In Germany a company called Sunmachine built a similar device albeit fed by wood pellets made from saw dust. So, even more carbon friendly. It only produced 3KW max out put and hence was aimed at residential properties. The company went bust as it couldn’t find the necessary working capital to bridge the gap between its sizeable order book and producing enough machines beforehand.

Reading this I couldn’t help but wonder if it’d work in Nigeria where the national grid has taken a hike. Even at $15,000 with development costs and profit, it’d still be viable but that depends on how much and the cost of gas the Beacon 10 requires to continuously function and whether it can operate for reasonably long off a gas cylinder.

This clean energy technology using nickel and hydrogen will be emerging onto the market this year or next. According to Forbes.com it will energy “too cheap to meter.” It is a silver bullet solution to cutting emissions, because people will switch rapidly to this clean energy technology, not because we dictate to them to cut emissions, but because the technology will save them money big-time. Here is a primer (I have much more material, but this is just an introduction for the sake of space):

Check out this third-party verification of a LENR reactor that will soon hit the market: http://arxiv.org/abs/1305.3913 “Given the deliberately conservative choices made in performing the measurement, we can reasonably state that the E-Cat HT is a non-conventional source of energy which lies between conventional chemical sources of energy and nuclear ones.” (i.e. about five orders of magnitude more energy dense than gasoline, and a COP of almost 6).

This phenomenon (LENR) has been confirmed in hundreds of published scientific papers: http://lenr-canr.org/acrobat/RothwellJtallyofcol.pdf

Too bad the article never got into the cost of the natural gas per Kw. Solar panels are now so cheap that even if the NG was free I suspect PV solar is still much more cost effective in Sunny climates like coastal California.

There also the issue of pollution. The article never mentions the amount for CO2 & other pollutants (if any) emitted. I suspect that going forward ANY power generation that involves burning anything (NG, wood, cow manure) is a dead end.

Good point on the cost of NG per kw. Would like to know that. Because of the high efficiency of the Stirling, it may be more efficient at turning NG into electricity than a big industrial turbine, and you wouldn’t suffer the 30% transmission losses. Will definitely need to be sussed out.